Breeding Crops for Enhanced Food Safety

Abstract

An increasing global population demands a continuous supply of nutritious and safe food. Edible products can be contaminated with biological (e.g., bacteria, virus, protozoa), chemical (e.g., heavy metals, mycotoxins), and physical hazards during production, storage, transport, processing, and/or meal preparation. The substantial impact of foodborne disease outbreaks on public health and the economy has led to multidisciplinary research aimed to understand the biology underlying the different contamination processes and how to mitigate food hazards. Here we review the knowledge, opportunities, and challenges of plant breeding as a tool to enhance the food safety of plant-based food products. First, we discuss the significant effect of plant genotypic and phenotypic variation in the contamination of plants by heavy metals, mycotoxin-producing fungi, and human pathogenic bacteria. In addition, we discuss the various factors (i.e., temperature, relative humidity, soil, microbiota, cultural practices, and plant developmental stage) that can influence the interaction between plant genetic diversity and contaminant. This exposes the necessity of a multidisciplinary approach to understand plant genotype × environment × microbe × management interactions. Moreover, we show that the numerous possibilities of crop/hazard combinations make the definition and identification of high-risk pairs, such as Salmonella-tomato and Escherichia coli-lettuce, imperative for breeding programs geared toward improving microbial safety of produce. Finally, we discuss research on developing effective assays and approaches for selecting desirable breeding germplasm. Overall, it is recognized that although breeding programs for some human pathogen/toxin systems are ongoing (e.g., Fusarium in wheat), it would be premature to start breeding when targets and testing systems are not well defined. Nevertheless, current research is paving the way toward this goal and this review highlights advances in the field and critical points for the success of this initiative that were discussed during the Breeding Crops for Enhanced Food Safety workshop held 5-6 June 2019 at University of California, Davis.

A Simple Assay to Assess Salmonella enterica Persistence in Lettuce Leaves After Low Inoculation Dose

“…Many of these foods can be eaten raw, and although this represents a practical advantage, it also makes them notoriously relevant to foodborne illnesses. Salmonella enterica is one of the most common human pathogens found in fresh produce (Bennett et al, 2018;Melotto et al, 2020). Previously, plants were thought to be passive vectors for human pathogens, but recent studies showed that S. enterica can induce plant defense responses (Meng et al, 2013;Garcia and Hirt, 2014;Melotto et al, 2014;Oblessuc et al, 2020).…”

Genomics and Marker-Assisted Improvement of Vegetable Crops

“…To increase genetic diversity and introduce novel loci into the cultivated lettuce, hybridization of elite cultivars with old heirloom varieties and related wild species has been common in pre-breeding programs. Such diversification of the primary gene pool may help developing cultivars with improved resistance or tolerance to biotic and abiotic stresses (Adhikari et al, 2019), better nutritional (Simko, 2019), and post-harvest qualities (Hayes and Simko, 2016;Damerum et al, 2020), water and nutrient use efficiencies (Simko, 2020a;Macias-Gonz alez et al, 2021), and potentially cultivars that are less hospitable to human enteric pathogens (Simko et al, 2015b;Melotto et al, 2020).…”

OMICs, Epigenetics, and Genome Editing Techniques for Food and Nutritional Security

“…Although the selection mechanisms used by plants significantly enrich the plant microbiome with beneficial microorganisms, such as plant growth-promoting rhizobacteria (PGPR) [ 76 ] and disease suppressing microorganisms [ 76 , 82 , 83 ], many researchers have shown that the rhizosphere and all plant compartments often contain both phytopathogens and human pathogenic bacteria as well as producers of toxins that can enter the food chain directly from plants [ 84 , 85 , 86 ]. Moreover, if a plant disease occurs, it not only promotes the multiplication of the pathogen, but is also accompanied by dramatic changes in the entire microbiome [ 87 ].…”